The present invention relates to a control technique for responding to the generation of an event, for example, to an effective technique applied to an interrupt control in a microcomputer.
In a typical interrupt control as the control technique for responding to the generation of an event, when a peripheral circuit generates an event signal, an interrupt controller receives the event signal. The interrupt controller outputs, for example, an interrupt factor responsive to the received event signal to a CPU as vector information, and requests interrupt processing from the CPU according to an interrupt signal. When the interrupt controller receives a plurality of event signals at the same time, the interrupt controller mediates the competing event signals according to an interrupt priority, and requests the interrupt processing higher in the priority from the CPU. In this situation, a difference may occur in a signal delay of a signal propagation path until the plurality of event signals generated at the same time arrives at the interrupt controller. In this situation, when the event signal lower in the interrupt priority is received ahead, the interrupt processing higher in the interrupt priority is postponed. Japanese Unexamined Patent Application Publication No. Hei-11 (1999)-203147 discloses a technique that focuses on such a problem.
In Japanese Unexamined Patent Application Publication No. Hei-11 (1999)-203147, for the plurality of event signals which is sequentially input, an interrupt prioritization of the event signals input every given duration is determined.